全文获取类型
收费全文 | 5254篇 |
免费 | 359篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 141篇 |
妇产科学 | 101篇 |
基础医学 | 803篇 |
口腔科学 | 338篇 |
临床医学 | 349篇 |
内科学 | 1341篇 |
皮肤病学 | 153篇 |
神经病学 | 388篇 |
特种医学 | 130篇 |
外科学 | 602篇 |
综合类 | 13篇 |
一般理论 | 3篇 |
预防医学 | 406篇 |
眼科学 | 74篇 |
药学 | 354篇 |
中国医学 | 57篇 |
肿瘤学 | 280篇 |
出版年
2023年 | 55篇 |
2022年 | 97篇 |
2021年 | 167篇 |
2020年 | 106篇 |
2019年 | 159篇 |
2018年 | 222篇 |
2017年 | 128篇 |
2016年 | 150篇 |
2015年 | 158篇 |
2014年 | 239篇 |
2013年 | 296篇 |
2012年 | 413篇 |
2011年 | 442篇 |
2010年 | 205篇 |
2009年 | 177篇 |
2008年 | 294篇 |
2007年 | 293篇 |
2006年 | 246篇 |
2005年 | 238篇 |
2004年 | 213篇 |
2003年 | 192篇 |
2002年 | 179篇 |
2001年 | 118篇 |
2000年 | 115篇 |
1999年 | 86篇 |
1998年 | 39篇 |
1997年 | 16篇 |
1996年 | 21篇 |
1995年 | 27篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 57篇 |
1991年 | 40篇 |
1990年 | 48篇 |
1989年 | 43篇 |
1988年 | 30篇 |
1987年 | 46篇 |
1986年 | 29篇 |
1985年 | 29篇 |
1984年 | 22篇 |
1983年 | 20篇 |
1981年 | 11篇 |
1979年 | 9篇 |
1978年 | 8篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 12篇 |
1972年 | 8篇 |
1970年 | 14篇 |
1966年 | 8篇 |
排序方式: 共有5635条查询结果,搜索用时 15 毫秒
31.
We report the singular case of an exceptionally large giant communicating artery aneurysm successfully treated with a direct surgical approach. The clinical presentation was a relatively short history of frontal headache. In the pre- and postcontrast CT scans the lesion mimicked an intracranial tumor. At surgery the intraluminal thrombus was partially removed with an ultrasonic surgical aspirator; the decompression allowed the isolation and subsequent temporary dipping of the tracts A1 and A2 of both the anterior cerebral arteries. It was then possible to complete the thrombectomy and to dip the neck of the aneurysm. The report emphasizes the indispensable role of MRI for the accurate diagnosis of giant intracranial aneurysms and the recent improvement of the surgical results concerning this category of aneurysms (mainly related to the present wider availability of technical surgical instrumentation). 相似文献
32.
A number of neurotoxins from venoms of invertebrates and plants are ligands for voltage-gated Na+ channels and are useful tools for studying Na+ channel function and structure. Using whole-cell recordings from vagal afferent nodose neurons, we studied neurotoxins that target Na+ channels. We asked whether Ts3 (an α-scorpion toxin) and/or veratridine (a lipid-soluble toxin), could modify the TTX-resistant Na+ current generated by vagal afferent nodose neurons. Nodose TTX-resistant current was not affected by Ts3, whereas Ts3 slowed inactivation of the current generated by TTX-sensitive current component. We found that veratridine inhibited the TTX-resistant Na+ currents on rat nodose neurons. Interestingly, veratridine-modified Na+ channels developed a persistent current that accounted for the large tail current observed. We propose that veratridine modifies TTX-resistant Na+ channels through a mechanism distinct from its actions on other voltage-gated Na+ channels. 相似文献
33.
34.
35.
36.
Paola Ungaro Immacolata Cristina Nettore Fabiana Franchini Giuseppe Palatucci Giovanna Muscogiuri Annamaria Colao Paolo Emidio Macchia 《Nutrients》2022,14(15)
Ketogenic diets (KD) are dietary strategies low in carbohydrates, normal in protein, and high, normal, or reduced in fat with or without (Very Low-Calories Ketogenic Diet, VLCKD) a reduced caloric intake. KDs have been shown to be useful in the treatment of obesity, metabolic diseases and related disorders, neurological diseases, and various pathological conditions such as cancer, nonalcoholic liver disease, and chronic pain. Several studies have investigated the intracellular metabolic pathways that contribute to the beneficial effects of these diets. Although epigenetic changes are among the most important determinants of an organism’s ability to adapt to environmental changes, data on the epigenetic changes associated with these dietary pathways are still limited. This review provides an overview of the major epigenetic changes associated with KDs. 相似文献
37.
Enzymatic mild acidolysis lignins (EMAL) isolated from different species of softwood and Eucalyptus globulus were submitted to comparative analysis that included thioacidolysis, derivatization followed by reductive cleavage (DFRC), and DFRC followed by quantitative (31)P NMR (DFRC/(31)P NMR). While gas chromatography (GC) was used to determine the monomer yields from both thioacidolysis and DFRC, (31)P NMR studies quantified the various phenolic hydroxy groups released by DFRC. The monomer yields from thioacidolysis and DFRC were substantially different, with thioacidolysis resulting in higher yields. In contrast, an excellent agreement was obtained in the total number of beta-aryl ether structures determined by thioacidolysis and DFRC/(31)P NMR, indicating that the combination of DFRC with quantitative (31)P NMR overcomes, at least in part, the limitations presented by the DFRC method. Both thioacidolysis and DFRC/(31)P NMR were further used to better understand the lignin isolation process from wood. The results show that mild rotary ball milling minimizes, but does not prevent, the degradation of beta-O-4 structures during the early stages of wood pulverization. The extent of such degradation was found to be higher for E. globulus than for a variety of softwoods examined. Furthermore, the structures of the EMALs isolated at yields ranging from 20% to 62% were very similar, indicating structural homogeneity in the lignin biopolymer within the secondary wall. 相似文献
38.
de Faria DE Borges LV Peters VM Reis JE Ribeiro LC de Cássia da Silveira E Sá R Guerra Mde O 《Phytotherapy research : PTR》2008,22(2):185-189
The Gingko biloba extract is contraindicated during pregnancy and lactation due to the lack of information about its effects on these reproductive phases. Previous studies have shown that G. biloba extract contains components with estrogenic and antiestrogenic activities, thus nursing dams treated with the extract of this plant could show reduction in milk production, resulting in malnutrition and poor development of pups. This work analyzes the postnatal development of pups, whose mothers were treated with G. biloba extract during the lactation period. Nursing Wistar rats received 3.5 mg/kg/day of G. biloba aqueous extract, corresponding to the highest human dose. Clinical signs of maternal toxicity were evaluated. The growth rate, viability, survival during treatment and lactation indices of the pups were calculated. The physical, motor and sensorial development of the pups was also evaluated. No maternal signs of toxicity were observed. As there were no biological differences between control and G. biloba treated pups, it is possible to assume that, in this experimental design, the administration of G. biloba aqueous extract to nursing rats during the lactation period seems to be devoid of toxic effect to mothers and to the physical, motor and sensory development of the pups. 相似文献
39.